Technical Field
Exemplary aspects of the present disclosure relate to a light-emitting device.
Related Art
Certain types of image forming apparatuses alert a user to a paper jam by lighting up a lens disposed at a position where the paper jam is occurring with a light-emitting diode (LED). Such an image forming apparatus includes an LED and a lens disposed on an openably closable door. When the door is closed, the lens is lit up via the LED.
Similarly, certain image forming apparatuses alert a user to recognize a paper tray currently in use by lighting up a lens disposed in front of the target paper tray with the LED. Such an image forming apparatus includes the LED and the lens disposed on the side of the tray. The lens is lit up by the LED when the tray is closed.
However, when the LED and the lens are disposed in the above configuration, because both of the LED and the lens are fixed, the LED and the lens may contact each other when the door or the tray is open or closed. When the LED and the lens collide, the LED and the lens may be broken or damaged. Thus, considering variations in overstroke and the dimensional tolerances of the parts when the door or the tray is closed, at least 3 to 4 mm of separation between the LED and the lens is required lest the LED and the lens collide.
However, keeping that separation between the LED and the lens dissipates the light from the LED, necessitating an increase in power supplied to the LED. If the electric current to be supplied to the LED is increased, energy consumption also increases, so that the energy-saving effect of the LED is dissipated. Thus, a scheme to reduce the dissipation or loss of light from the LED becomes necessary.
JP-2011-158866-A discloses a technology including means to turn the LED on and off to identify a position of a device to be accessed by a user and to turn on the LED in the order of access if there are many points requiring the user's attention, to thus prompt a user to access each point in order.
However, the same does not describe a problem of loss of light amount in the light-emitting device such as an LED and no related technology is disclosed.